This invention relates to an optical pickup suitable for use in an optical disk drive and, in particular, to an optical pickup in which an objective lens is elastically supported by a suspension member.
With reference to FIGS. 1A-1D, a first one of conventional optical pickups of the type will be described. The first conventional optical pickup comprises a lens holder 11, an objective lens 12 held by the lens holder 11, a damper base 13, and four conductive wires 14 as a suspension member for elastically suspending the lens holder 11 to the damper base 13. A cover 15 is connected to the damper base 13 and extends to cover the lens holder 11. The lens holder 11 is provided with a coil unit (not shown) electrically connected to the conductive wires 14. The cover 15 is provided with a magnet (not shown) placed adjacent to the coil unit. The cover 15 is held by a frame of a optical disk drive.
Each of the conductive wires 14 penetrates the damper base 13 to have an end portion 14a exposed from the damper base 13. A flexible printed circuit (FPC) 16 is attached to the damper base 13. The FPC 16 has a plurality of electric circuits connected to the conductive wires 14 in the manner which will later be described. The coil unit is supplied with an electric signal from a control part of the optical disk drive through the FPC 16 and the conductive wires 14.
For connection of the suspension wires 14 to the FPC 16, the end portion 14a of each of the conductive wires 14 are provisionally fixed to the damper base 13 by the use of an adhesive as illustrated in FIGS. 1A and 1B. When the first conventional optical pickup is thereafter assembled into a housing of the optical disk drive, the end portion 14a is soldered to the FPC 16 as illustrated in FIGS. 1C and 1D.
The first conventional optical pickup is disadvantageous in the following respects. In a production process, energizing is carried out to measure various characteristics by the use of a measuring instrument before the first conventional optical pickup is assembled into the housing. At this time, a probe of the measuring instrument is brought into direct contact with the end portion 14a of each of the conductive wires 14, i.e., the terminals, which are only provisionally fixed by the adhesive. Therefore, the conductive wires 14 are inevitably applied with additional force exerted by the probe. This makes it difficult to accurately measure kinetic characteristics. Furthermore, since the conductive wires 14 are thereafter fixed to the FPC 16 by soldering, the adhesive may be melted by heat. In this event, the objective lens 12 is moved out of position.
With reference to FIGS. 2A-2D, a second one of the conventional optical pickups will be described. Similar parts are designated by like reference numerals.
In the second conventional optical pickup, an intermediate substrate 17 is attached to the damper base 13. The end portion 14a of each of the conductive wires 14 are soldered to the intermediate substrate 17, as illustrated in FIGS. 2A and 2B. In this state, various characteristics are measured by the use of the measuring instrument. When the second conventional optical pickup is thereafter assembled into the housing, the FPC 16 is soldered to a plurality of connection lands 18 formed on the intermediate substrate 17, as illustrated in FIGS. 2C and 2D.
In order to measure various characteristics before assembling, the intermediate substrate 17 is provided with test pins (not shown) which are brought into contact with the probe. With the second conventional optical pickup, the conductive wires 4 may not directly be contacted by the probe and are therefore prevented from being applied with the additional force described in conjunction with the first conventional optical pickup. However, the number of parts is increased by provision of the intermediate substrate 17. In addition, the manhour required in the production process is also increased.